the story that's been coming out in bits and pieces all afternoon long, but now we are learning the fbi had begun an investigation prior to this announcement trying to see if america's national security had been compromised. gary newenberg has been following this still developing story and he has the latest. >> reporter: stories like this often come as surprise, but it's not a cliche to use the word shock in this case. petraeus had a squeaky clean reputation as a by the book career general who climbed the military ladder quickly with success